JPS634595A - Discharge lamp starter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to a discharge lamp starting device using a bimetal switch.

[Background Art] Usually, this type of discharge lamp starting device is as shown in FIG.
A bimetal switch S- is connected via a first diode D1 between secondary side terminals a and b of a discharge lamp La connected to a power source E via a stabilizing element Ba, and the bimetal switch S- is connected in parallel with this first diode D1. A series circuit of a first heater H1 and a Zener diode Dz is connected to bend the bimetal switch Sw in the I$11m direction, and a connection point C between the heater H7 of PF51 and the Zener diode Dz is connected to the bimetal switch SW. A second heater H that bends the bimetal switch S=1 in the closing direction is connected between the other end and the other end through a series circuit of the diode D2 of rtS2 and the resistor R1.
It is constructed by connecting two. Note that Cn is a noise prevention capacitor.

FIG. 2 shows the structure of the bimetal switch 5Ill, in which each heater H+, i' (2 is configured to heat the bimetal pieces B, B2 and curve them in the same direction. Both bimetal pieces B,,B
Contact No. 2, W S + + 32, is closed, and after the lamp is lit, the amount of heat generated by the heater H overcomes the contact, and the contact is kept open. However, if the lamp is not lit due to a startup error, heater H2 is closed.
The amount of heat generated by the contact point S , , S , is closed. By using both bimetal pieces with the same characteristics, the effects of changes in power supply voltage and ambient temperature can be compensated for.

In the above configuration, when the 'Ki source is turned on, preheating main flow flows to the lamp La via the first diode D1 and the bimetal switch 5IIl in the positive half cycle of the power supply voltage.
In the negative half cycle, current is supplied to the first (opening) heater H0 through the Zener diode Dz, so the heat generated by the heater H1 opens the bimetal switch SLI and starts the lamp La. After starting, a, brJ
Is l'rl pressure the lamp lighting voltage? As it decreases, a-+D only in the positive half cycle, → H1 → D2 → R1 → H2 →
A current flows through the path b, and the voltage applied across the separation heater H is made constant by the Zener diode Dz. The calorific value of the second (closing) heater H2 at the time of the main octopus is set low, and therefore the bimetal switch Sll+ is held in the open state due to the difference in the calorific value of both heaters H, , H2. If starting fails or starts immediately after the light goes out, the contact remains open and a.

Since the voltage across the bimetal switch 5l11 increases, the voltage across the closing heater H2 increases, but the voltage across the opening heater H1 remains constant as it remains constant.
is forced closed, supplying a reheating current to the lamp La. When the bimetal switch Sur closes, the power supply to the closing heater H2 is stopped! As the temperature of the bimetallic piece B2 at tS2 decreases, the amount of current applied to the opening heater H1 increases and the first bimetallic piece B bends further, so the bimetallic switch Sw immediately opens and the lamp La is restarted.

In the conventional example described above, when lighting fails and the bimetal switch SII+ is closed due to heat generated by the opening heater H2, the first diode D and the bimetal switch S
Since the short-circuit between a and b is caused by
will open again in a short time. The time during which this connection is closed, that is, the reheating time, is usually about 0.1 to 0.2 seconds, but this time is slightly insufficient for reheating the lamp, and depends on conditions such as ambient temperature. had the disadvantage that it was difficult to restart or was prone to incomplete lighting (half-wave lighting). In this case, the most desirable reheating time is 0.4 to 0.5 seconds.

[Objective of the Invention 1] The present invention has been made to solve the above-mentioned problem α, and improves restart performance by ensuring sufficient lamp preheating time at restart in a discharge lamp starting device using a bimetal switch. The purpose of this is to improve the

[Disclosure of the Invention 1] Accordingly, the present invention connects a bimetal switch consisting of two opposing bimetal pieces between the secondary side terminals of a discharge lamp connected to a power source via a stabilizing element, and connects the bimetal switch in series with the bimetal switch. Curve the first bimetal piece in the opening direction! ?
'In a discharge lamp starting device which is connected to the heater of S1 and a second heater which bends the bimetal piece of PIS2 in the closing direction in parallel to the bimetal switch, the first bimetal piece of The resistance value is smaller than the resistance value of the second bimetal piece, and conventionally the curvature of both bimetal pieces due to self-heating was canceled out by using the same characteristics for both pieces. In the present invention, by increasing the self-heating amount of the second (closing side) bimetal piece and increasing its curvature, the return of the second bimetal piece after the contact is opened in the event of a startup failure is delayed, and the resetting is possible. ``It is characterized by an extended heating time.

[Embodiment 1] FIG. 1 shows an embodiment of the present invention, and its basic circuit configuration and operation are exactly the same as those described as the conventional example. In the present invention, in the bimetal switch SW shown in FIG.
1 and the first bimetal piece B with Pt52 (
I7! ) The second bimetal piece B2 to which the heater H2 is attached can be made of materials with different specific resistance values, or by changing the shape, thickness, etc.
The resistance value of bimetal piece B is f! The resistance value is smaller than that of the bimetal piece B2 of S2.

In Fig. 1, when the power is turned on, a preheating current flows through the diode D and the bimetal switch S in the positive half cycle, and the preheating current flows through the zener diode D in the negative half cycle.
When current is supplied to the heater H1 through z, the bimetal piece B1 of fPjl bends, and the contacts S,, S, open and start the lamp, the lamp is not lit due to a lamp starting error or other reason. , the power supply voltage is applied between terminals a and b, and the amount of heat generated by heater H2 increases compared to the amount of heat generated by heater H, which is kept at a constant voltage, and the curvature of bimetal piece B2 of Q'S2 becomes large. Contact point S ,,S
, is closed. At this time, the heat generation amount of heater H1 increases and at the same time heat generation of heater H2 stops, so conventionally, the temperature of bimetal piece B2 immediately decreased and the contacts S, S2 opened in a short time. , in the present invention, the amount of self-heating generated in both bimetal pieces B, , B by the re-warming current flowing through both bimetal pieces B, , B2 during contact opening is higher in the second bimetal piece B2. Since it is configured to be larger, the temperature drop of the second bimetal piece B2 is delayed accordingly, and the opening timing of the contacts S2, S2 can be delayed.

[Effect 1 of the Invention As described above, the present invention uses a bimetal switch consisting of two opposing bimetal pieces to heat the first bimetal piece to cut off the preheating current at the time of initial startup, and to cut off the preheating current at the time of restart. A discharge lamp starting method in which the second bimetal piece is heated to close the contact, and this contact closure short-circuits the heater of the second bimetal piece, and the bimetal piece returns to cut off the re-preheating current. In the apparatus, the resistance value of the first bimetal piece is made smaller than the resistance value of the second bimetal piece,
Since the self-heating of the bimetallic piece is used to delay the return of the second bimetallic piece, it is possible to secure a sufficient reheating time, which was often insufficient in the past, to ensure restart. This has the advantage of being possible.

[Brief explanation of drawings]

Fig. fPjl is a circuit diagram showing one embodiment of the invention, and Fig. 2 is a perspective view of the same essential parts. E...AC power supply, Ba...stability element, La...lamp, Sa+...bimetal switch, s1 and Vs2
...Touching 5 parts, B1...First bimetal piece %B2.
...Second bimetal piece, Hl...First heater, R
2...fIS2 heater, Dl...first diode, D2...second diode, Dz...Zener diode, R1...resistance. Agent Patent Attorney Ishi 1) Ue 7th Figure 1 Mei 2 Ward

Claims (1)

[Claims] (1) A bimetal switch consisting of two opposing bimetal pieces is connected between the secondary side terminals of a discharge lamp connected to a power supply via a stabilizing element, and a first bimetal switch is connected in series to the bimetal switch.
A discharge lamp starting device comprising: a first heater for curving a bimetal piece in an opening direction; and a second heater for curving a second bimetal piece in a closing direction in parallel with a bimetal switch. A discharge lamp starting device characterized in that the resistance value of the first bimetal piece is smaller than the resistance value of the second bimetal piece.